I had previously owned the Yocan Uni which I had for quite some time. I was happy with it but eventually it became inconsistent whether it would work or not so I looked for a replacement. I decided to try the newer version, the Yocan Uni Pro. I am even happier with this than I was with the original.
On the Uni Pro you can adjust the voltage by 0.1V between 2.0V and 4.2V. You can precisely fine tune your vaping experience by adjusting the voltage to best suit your needs. The Uni only has 3 preset voltage settings in comparison.
I also like the new material it appears to be made of. I chose black but many color choices. The displays when you use it are a nice feature and much better as well.